Filling online grocery orders by having staff walk the aisles is slow. Micro-fulfilment uses compact automated systems, often robots retrieving items from dense storage, placed in or near stores, to assemble orders quickly close to where customers are.
Putting automation near the customer speeds up delivery and pickup and uses space efficiently. The systems handle packaged goods well, while fresh and awkward items still need people, and the equipment is a real investment, so it suits certain stores and demand levels, but it represents a practical way to make online grocery service faster and more reliable.